Two Jonny May tries saw Gloucester move above Northampton in the Aviva Premiership as they inflicted on the hosts their fifth home defeat of the season.

For so long a fortress, it was Northampton's third defeat at Franklin's Gardens in the league, and it was down to some magnificent Gloucester defence as Saints were twice stopped on the line and held up over it once, with the back row duo of Sione Kalamafoni and Akapusi Qera superb.

May conjured a piece of magic in the first half and then pounced on a dropped ball for a 70 metre try for his second. After that it was dogged defence from Gloucester who took revenge for losing at home to Northampton at the start of the season.

The first scrum of the game produced a penalty for Stephen Myler to give the home side an early 3-0 lead.

But Gloucester drew level immediately through the boot of full-back Rob Cook and they were never behind again.

Cook made it 6-3 after some aerial ping-pong ended with Northampton making the mistake and being caught offside and Myler had a chance to draw Northampton level, but pulled his kick from 10 metres in from the left touchline wide.

On 20 minutes May, playing on the wing, popped up in midfield from a lineout move to turn George Pisi inside out and sprint clear of Lee Dickson for the first try of the game. It gave Gloucester an 11-3 lead as Cook missed the conversion.

Mike Haywood looked like he was about to draw Northampton level after a neat offload from Ben Nutley on the Gloucester 22 put him clear, but number eight Kalamafoni hauled him down inches short by his shirt collar. Instead Myler cut the visitors' lead to five with a 28th minute penalty.

But a scrum penalty for Gloucester against tighthead Tom Mercey saw Cook make it 14-6 and when Mike Tindall got over the ball, the full-back added three more. Cook then ran back a James Wilson kick with only a great tackle from Jamie Elliott stopping May grab his second try. But GJ van Velze was caught lying on the ball two metres from his line and was yellow-carded four minutes before half-time.

At 17-6 in front Gloucester went for the scrum and a penalty try against Northampton's seven-man pack, four times it was reset, but on the fifth Rupert Harden was penalised for not binding and the home side escaped.

It was made immaterial two minutes into the second half when James Wilson dropped a pass and May raced home from 70 metres for his second try. Cook made it 24-6 for the visitors.

Two minutes later May was sin-binned as Gloucester tried to stop a five metre lineout drive and the home side thought they had scored a try when they went again but the TMO saw Samu Manoa drop the ball as he went to put it down.

Northampton kicked to the corner again on 54 minutes and this time Phil Dowson jinked and powered his way over. But Northampton celebrations were cut short as Manoa was yellow-carded for a punch after the try to reduce the game to 14 against 14 until May returned two minutes later and then Myler missed the conversion.

With 15 minutes to go another Northampton lineout drive went steaming towards the line, but was held up and when Mark Sorenson was turned over on the line the Gloucester coaching staffs were punching the air.

With seven minutes to go Cook slotted his fifth penalty to signal a mass exodus of home fans.